Metabolic studies of Rhesus monkeys or rabbits subjected to hemorrhagic shock with reinfusion will be performed to delineate the changes in tissue amino acid metabolism and protein turnover. Animals will be studied sequentially for up to one month after shock and reinfusion to define the time course of the metabolic changes and their return to normal. Muscle, adipose tissue and liver will also be studied to determine changes in metabolic parameters characteristic of each tissue: glucose and amino acid metabolism of muscle, lipolysis and lipogenesis of adipose, and glycogen content and histology of liver. Endocrine factors associated with hemorrhagic shock will be studied by using adrenalectomized and/or pancreatectomized monkeys receiving replacement infusions of steroids and/or insulin and/or glucagon before and after shock. Thyroidectomized monkeys will be studied receiving thyroxine replacement before and after shock. The animals will be given permissive levels of the replaced hormones, but no changes of the type commonly observed following shock will be permitted. The changes in tissue metabolism in the absence of the usual shock induced endocrine changes will therefore be definable. BIBLIOGRAPHIC REFERENCES: Ryan, N.T.: Metabolic adaptations for energy production during trauma and sepsis. Surg. Clin. No. Amer. 56:1073-1090, 1976. Ryan, N.T. and Clowes, G.H.A., Jr.: Metabolic effects of glucose-insulin potassium during experimental intraperitoneal sepsis. Accepted for publication, Dec. 1976, issue of Circ. Shock.